Polyethylenimine synthesis

Water-soluble polyethylenimine of molecular weight 30,000 has been used for the synthesis of a model tetrapeptide by Blecher and Pfaender 161). The /V-carboxyanhy-dride method was used for the coupling, and by ultrafiltration excess reagents were removed. An enzymatic method was employed in this case for the splitting of the peptide from the support. 

Graft Copolymers of Nucleic Acid Bases onto Polyethylenimine 5.1 Polymer Synthesis... 

Blecher and Pfaender used polyethylenimine (PEI) of molecular weight 30000 as a water-soluble support for the synthesis of a model tetrapeptide This polymer is designed for use in combination with the N-carboxyanhydride coupling method. 

Sagara K, Kim S W (2002). A new synthesis of galactose-poly (ethylene glycol)-polyethylenimine for gene delivery to hepatocytes. /. Control. Rel. 79 271-281. 

Brissanlt B, et al. (2003). Synthesis of linear polyethylenimine derivatives for DNA transfection. Bioconjug. Chem. 14 581-587. 

Brissault, B., Kichler, A., Guis, C., Leborgne, C., Danes, O., and Cheradame, H. 2003. Synthesis of hnear polyethylenimine derivatives for DNA transfection. Bioconjugate Chemistry 14 581-587. 

FIGURE 28.1 Proposed reaction scheme for synthesis of galactosylated chitosan-graft-polyethylenimine (GC-g-PEI). (From Jiang, H.L. et ah, Gene Ther., 14, 1389, 2007b. With permission.)... 

He P, Greenway G, Haswell SJ (2008) The on-line synthesis of enzyme functionalized silica nanoparticles in a microfluidic reactor using polyethylenimine polymer and R5 peptide. Nanotechnology 19 315603-315610... 

Other chelating polymers related structurally to polyethylenimine and polyethyl-enimine have been derived from cyclopolymerized diallylamines. The structure and properties of these resins have been reviewed by Hodgkin. The attempted synthesis of novel linear poly(lV-alkylethylenimine)s, for metal complexation, by demethylation of ionene polymers has been described.The reaction (involving treatment with UAIH4) was successful only with ionene oligomers. 

A water soluble polyethylenimine support has been developed for peptide synthesis using A -carboxylic anhydrides in a sequential method of peptide synthesis. The final polymer-peptide cleavage was effected by tryptic digestion (Pfaender et aL, 1975). 

Scheme 2 Synthesis of linear polyethylenimine (LPEI) and branched polyethylenimine (BPEI).

Ring-opening polymerization evidently constitutes another method for the synthesis of regular internal structures [8]. In order to obtain a strictly linear polyampholyte with a repeating unit as small as possible, A -alkyl substituted ethylenimines have to be used, since conventional unsubstituted polyethylenimine has a highly branched structure. The synthesis of strictly linear polyethylenimine has, however, been described recently by Saegusa and coworkers by isomerization polymerization of 2-oxazoline [9]. 

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